1. Field of the Invention
The invention is directed generally to a computer tomography apparatus with a rotating frame on which an x-ray emitter, a radiation detector, and associated detector electronic components are carried and, particularly, to a cooling system for the associated detector electronic components.
2. Discussion of the Related Art
In the art relating to computer tomography or zeugmatography, an x-ray emitter or radiator is located on an annular frame which rotates about a patient placed in a center hole of the frame. The x-ray emitter emits fan-shaped beam of x-rays through the patient which are picked up by detectors aligned with the focal point of the x-ray radiator. In this manner, cross-sectional or transversal slice images of the patient's body are produced.
It has long been noted that the electronic components associated with the detectors, the so-called electronics, generate a great amount of undesirable heat. As a result, attempts have been made to effectively remove or eliminate the heat generated by the electronics associated with the computer tomography apparatus detectors.
German patent application No. 34 36 867 discloses one attempted solution. A computer tomography apparatus is provided with a channel between the rotating frame and the stationary frame. The channel is traversed by a coolant. Additionally, cooling ribs of the rotating frame project into the channel.
Japanese patent application No. 57-50673 discloses a computer tomography apparatus wherein individual detectors are located in a collimator, mainly upon collimator plates. The collimator plates serve as cooling fins for the detectors. Additionally, cooling lines containing coolant are provided which penetrate through the fins to carry heat away from the fins. However, no disclosure is made as to the type of coolant used. Furthermore, no disclosure is made as to whether the electronics associated with the detectors are similarly cooled.
European patent application No. 0 109 206 discloses a fourth generation computer tomography apparatus which includes a stationary detector ring with detector modules. The detector ring is cooled by cooling air that is blown into the detector modules through channels or shrouds. The cooling air circulates within a closed circulation system which includes evaporators located on the stationary ring. The cooling coils of the evaporators are not employed directly at the electronics associated with the detectors.
British patent application No. 2 026 812 discloses a third generation computer tomography apparatus which employs a closed circulation cooling system having coolant pumps and an x-radiator mounted on a rotating frame. Oil is used as the coolant. Neither an evaporator nor a condensor are utilized. Moreover, the cooling oil is used primarily to cool the x-ray tube and not the detector electronics.